Polyvinyl chloride (PVC) is widely used in a variety of applications. PVC is utilized in making rigid articles such as pipe, house siding, phonograph records, automotive parts, and household appliances. PVC is also utilized in manufacturing flexible items, such as packaging films, gaskets, furniture upholstery, wall coverings, garden hoses, shower curtains, car tops, floor mats, and detergent bottles. PVC can be made by utilizing suspension polymerization, mass polymerization, emulsion polymerization, or solution polymerization. Suspension polymerization is the most widely used technique for preparing PVC. In suspension polymerizations monomer droplets are suspended in an aqueous polymerization medium by a combination of vigorous agitation and protective colloids. Such polymerizations are generally initiated by free radicals which are produced by the thermal decomposition of peroxides.
U.S. Pat. No. 3,879,364 discloses the utilization of a seeding product in the polymerization of vinyl chloride monomer into polyvinyl chloride. The seeding product contains all of the initiator which is required for the main polymerization. U.S. Pat. No. 4,091,197 suggests activating the initiator with a metal complex which is formed by the reaction between a water-soluble metal salt and a complexing agent. U.S. Pat. No. 4,091,197 states that these complexes are utilized in proportions such that the molar ratio of metallic complex to initiator is between 0.1 and 10.